The purpose of this study is to determine whether medical or surgical castration in men with prostate cancer is associated with a change in their ability to metabolize drugs. If any similarity exists between male humans and rats in this regard, orchiectomy would be expected to cause a clinically significant decrease in drug metabolism activity. Study Hypothesis: There is a statistical and clinically significant difference in the activity of hepatic drug metabolism in men before and three months after medical or surgical castration.